Recent work in
non-human primates has shown enhanced in vivo visualization of subtle
features of myeloarchitecture based on T1 contrast. Here, extending this work
to humans, a 3D MPRAGE was optimized to enchance T1 contrast in high myelin
content gray matter (GM) while suppressing signals from the remaining GM. We
show excellent myelin visualization within GM in primary visual cortex, and
spatially detailed T1 contrast variations in extra-striate visual cortex,
possibly due to variations in myelin content as suggested by histology. This
enhanced myelin sensitivity can bridge between in vivo functional
imaging, and histological mapping of cortical micro-architecture in humans.